The present invention relates to axial flow chromatography columns, particularly to adjustable bed axial flow columns, and more particularly to an improved axial flow column which allows for quick bed adjustment, minimizes dead volume gap, utilizes lens-shaped frits, and provides easy access for cleaning and packing the column.
Chromatography is a term applied to a wide variety of separation techniques based upon the sample interchange between a moving phase, which can be a gas or liquid, and a solid stationary phase. When gas is the moving er mobile phase, the technique is termed gas chromatography and when liquid is the moving or mobile phase, the technique is termed liquid chromatography.
Separation techniques are generally classified into either analytical or preparative depending on the objective. In analytical separations, the objective is high resolution separation, identification and quantification of the various components of a sample mixture. In preparative chromatography the objective is the isolation of pure quantities of the constituents in the sample.
Such separation techniques include liquid absorption chromatography used for organic and biochemical analysis; ion exchange chromatography used for separation of ionic species; affinity chromatography based on the attraction of a ligand for a given component of the sample bonded to the solid stationary phase; and liquid-liquid or partition chromatography which involves the use of a thin layer of the sample dissolved in an appropriate solvent liquid held in place on the surface of a porous inert solid serving as the stationary phase.
In the chromatographic process, it is customary to pass a mixture of the components to be resolved in a carrier fluid through a chromatographic column or apparatus which includes a separation or resolving zone, such as a stationary phase which generally consists of a material or medium which has an active absorptive function for separating or isolating the components in the carrier fluid. The separation or resolving zone usually takes the form of a column, either axial flow or radial flow type, through which the carrier fluid passes. A major problem with the use of prior art axial flow chromatographic columns is the difficulty encountered in obtaining a uniform fluid flow across the column and through the separation medium. Numerous prior types of columns, media or separation bed arrangements, have been developed to provide effective separation of the various components of a sample solution as a carrier fluid is directed through the medium in the column. These prior efforts, dealing with axial flow type columns, are exemplified in U.S. Pat. Nos. 3,422,605 issued Jan. 21, 1969 to R.P. Crowley; No. 3,453,811 issued Jul. 8, 1969 to R.P. Crowley; No. 3,780,866 issued Dec. 25, 1973 to L.V. Ek et al; No. 3,856,681 issued Dec. 24, 1974 to C.N. Huber; No. 4,116,046 issued Sep. 26, 1978 to S. Stein; and No. 4,496,461 issued Jan. 29, 1985 to G. Leeke et al.
While there have been significant advancements in the field of chromatography, there is still a need for the optimization of chromatographic performance by the elimination or minimization of dead volumes in the columns, improving flow through the columns, providing for easy packing and unpacking of the separation medium, reducing contamination and improving sanitation, as well as providing means for easy adjustment of the bed of the columns. The present invention is directed to providing such optimization by utilizing V-ring seals, lens-shaped bed support frits, one-piece construction of the inlet tube and adjuster head, easy access for cleaning, and a snap-action locking lever for rapid movement of the bed adapter.